Objective: Recent experimental evidence indicates that angiogenesis affects tumor growth and metastasis. Vascular endothelial growth factor (VEGF) is considered to be an important regulator of tumor angiogenesis. The present study was designed to examine the role of VEGF on angiogenesis and lymph node metastasis in primary nasopharyngeal carcinomas (NPCs).
Study design: Formalin-fixed paraffin-embedded biopsy specimens were obtained from 29 primary NPCs that consisted of 22 differentiated nonkeratinizing carcinomas and seven undifferentiated carcinomas.
Methods: Microvessels were highlighted by staining endothelial cells with von Willebrand factor (VWF) using immunohistochemical techniques, and were counted (per x 400 field) in the most active area of angiogenesis on light microscopy. The expression of VEGF was also studied with immunohistochemistry. Positive ratio for VEGF was graded on a scale of 1 and 2. Scale 1 represents patients with less than the mean value of the positive ratio, and scale 2 represents patients with more than the corresponding value.
Results: There was a significant correlation between increased microvessel count and the progression of regional lymph node involvement. The microvessel counts and the progression of N factor were significantly higher in scale 2 patients than in scale 1 patients.
Conclusion: These results suggest that VEGF plays an important role in lymph node metastasis through induction of angiogenesis in NPCs.